Global Volcanism Program | Image GVP-03299
Steam rises from hot springs on the floor of the Long Valley caldera. Hot springs, fumaroles and active hydrothermal alteration are found throughout much of the caldera, but are particularly prevalent in the SE caldera moat area and on the flanks of the resurgent dome. The Sierra Nevada Range towers above the SW caldera margin in the background.
Photo by Larry Mastin, 1991 (U.S. Geological Survey).